Would you call Windows "open source" just because you run a few open source apps on it?
Google is slowly but surely turning more and more components of Android into closed source code. This is a targeted effort to kill AOSP and lock consumers into their ecosystem. The end result will probably look a lot like macOS: a few open source parts, but primarily a proprietary stack.
If the bootloader, all of the services, the kernel, the window manager, etc were open source, but edge was closed source and bundled in a separate version of Windows then yes I would consider Windows an open source operating system.
Because the desktop OS is used for so much more. But if the core functionality is missing, the point is lost. A better analogy, as you like to play games, is a VPN company releasing their app as open source, after being critiqued for privacy issues. Only to find out just the GUI was released but the rest can be installed using a plugin system.
The analogy is lost here because the core is open source but the GUI is not. Core system services do most of the heavy lifting for these apps and that remains in AOSP.
A lot of people still don't see how the operating system as a whole is open source, not having properly supported open source apps is not the best, but while we can make apps and/or update the aosp versions, we can't make an operating system...
